Short oven, burned bottoms

- The oven is short, compared to what I'm used to. About 16 inches of space.

- The oven, strangely doesn't have a pre-heat feature, and I didn't have an operating oven thermometer.

- I'm following the Tartine Country Bread method. And decided to brave the unknown but have never experienced the below issues before.

Loaf number 1: I pre-heated the Dutch Oven, plopped the proofed (in the fridge overnight) dough in, and got great oven spring. After the baking time, I realised that the bread's bottoms were burnt.

Loaf number 2: Got okay oven spring and I took the bread out before it was completely done on the top but the bread's bottom was burnt once again.

My next step in experimentation is to ensure the temperature is correct, though my worry is that the Dutch Oven Method isn't going to work for an oven this short, as the bottom will always be too close to the heat.

Any ideas on what I may be doing wrong? And will I need to start using a stone+steam method?